The present application generally relates to powered seats, and more particularly, to a system and method for calibrating a powered seat.
Modern airplane seats, and in particular, seats in the premium sections of passenger airplane are powered and adjustable between a number of seating positions. Some seats may be adjustable from an upright position to a reclined position, while others can recline to a substantially flat position in order to function as a bed. Additionally, some airplane seats have a head rest and a foot rest that can be adjusted to provide a comfortable position for each passenger. The various adjustable features of the seat are accessible and controllable with a passenger control unit, which may be a keyboard-type of input device with a display. The passenger control unit may also provide the passenger with the ability to adjust the environmental conditions around the seat, such as lighting, temperature and the like. Furthermore, the passenger control unit can also allow the passenger to operate various entertainment devices and features associated with the seat.
A seat must be calibrated after the initial built or at any time an actuator(s) or a controller is replaced during the service of the seat. The purpose of the calibration is record/store positional data in the controller of all actuators installed in the seat at two extreme travel positions, the two extreme travel/reference positions generally are most upright position which is called TTL (taxi take-off and landing) and BED position. In the TTL position all seat components/axis e.g. leg rest, footrest or recliner, are fully stowed and in the BED position all seat components/axis are at fully extended positions. After the calibration, all actuators always travel within two the stored limits, the motion is managed by the seat controller based on the motion program stored in a memory of the controller. Only after calibration, the seat can be used per its designed intent.
In order to calibrate a seat, the first step involves manually moving the seat to a known reference position. This reference position may be the Taxis-Takeoff-Landing position of the seat, which typically is a position where the seat is at its most upright position. In the second step, the actuators of the seat are all manually moved to the BED position, which is the most extended position of the seat so that it can be used for sleeping. In a third step, the actuators are all manually moved to the TTL position and a calibration button on the passenger control unit is depressed. The manual movement of seat in the first to the third steps may be necessary to ensure that the operating range of a potentiometer which senses the motion of the seat is compatible with travel range of the seat. During the first three steps, should the potentiometer reach its end of travel before the travel limit of the seat has been reached, a gear which is coupled to the slip clutch and a shaft of the potentiometer slips. Accordingly, moving the seat in the first three steps ensures that the potentiometer would turn through out the mechanical travel range of the seat and sense the position of the seat as opposed to slipping and not correctly sensing the position. In a fourth step, the actuators are all manually moved to the BED position and the calibration button on the passenger control unit is depressed. In a final step, the seat is electrically moved back to the TTL position. Each of the first four step of the above-described process may take more than two minutes and the final step may take more than one minute. Thus, a typical calibration process for a powered seat may take more than nine minutes.
Based on the above, there is a need for a calibration process that is simpler to perform, faster and requires less operator intervention.